org.eclipse.ui.trace.internal.TracingComponentComparator.java Source code

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Here is the source code for org.eclipse.ui.trace.internal.TracingComponentComparator.java

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/*******************************************************************************
 * Copyright (c) 2011 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.trace.internal;

import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;
import org.eclipse.ui.trace.internal.datamodel.TracingNode;

/**
 * A Comparator for ordering the list of traceable bundles visible in a viewer in alphabetical order
 */
public class TracingComponentComparator extends ViewerComparator {

    /**
     * Either the first or second object are null - so compare them to ensure they are put in the right order.
     * 
     * @param object1
     *            The first object to compare
     * @param object2
     *            The second object to compare
     * @return Return 0 if both objects are null; Returns -1 if object1 is null and object2 is not null; Returns 1 if
     *         object1 is not null and object2 is null.
     */
    private int compareNullCases(final Object object1, final Object object2) {

        int result = -1;
        // take care of the null cases
        if ((object1 == null) && (object2 == null)) {
            result = 0;
        } else if ((object1 == null) && (object2 != null)) {
            result = -1;
        } else if ((object1 != null) && (object2 == null)) {
            result = 1;
        }
        return result;
    }

    @Override
    public int compare(final Viewer viewer, final Object object1, final Object object2) {

        int result = -1;
        if ((object1 == null) || (object2 == null)) {
            // take care of the null cases
            result = this.compareNullCases(object1, object2);
        } else {
            // neither object are null
            if ((object1 instanceof TracingNode) && (object2 instanceof TracingNode)) {
                String name1 = ((TracingNode) object1).getLabel();
                String name2 = ((TracingNode) object2).getLabel();
                if ((name1 == null) || (name2 == null)) {
                    // take care of the null cases
                    result = this.compareNullCases(name1, name2);
                } else {
                    result = name1.compareTo(name2);
                }
            } else if (object1 instanceof String && object2 instanceof String) {
                String label1 = (String) object1;
                String label2 = (String) object2;
                result = label1.compareTo(label2);
            }
        }
        return result;
    }
}